“Immunization is widely regarded as one of the most effective and beneficial
tools for protecting the public’s health.” – IOM 2001

Vaccines give people immunity to specific infectious diseases, protecting them from potentially life-threatening illnesses. They also protect communities from epidemics because immune people do not catch diseases or efficiently pass them on to others.

Certain infectious bacteria, viruses, and parasites depend entirely on human hosts; they are not found elsewhere in nature. These organisms and the diseases they cause can be totally eradicated by vaccinating people.